APPLICATION: Waste Water Treatment Plant

COMMERCIAL OPERATION: Phase I – June 1989 Phase II – September 1990

PLANT CAPACITY, PRIMARY CLARIFIERS:

Total Primary Capacity: 230 million gallons per day

Four at 20 MGD

Five at 30 MGD

PROJECT IDENTIFICATION AND PARTICIPATING CONTRACTORS:

Sanitary District of Decatur, Illinois

S.P.C.M., SVERDRUP (Overall Contract Management)

Crawford Murphy & Tilly, Inc. (Designers)

Bainbridge, Gee, Milanski & Associates, Inc.

Johnson Controls, Inc. (Phase I I&C Contractor)

MMR Constructors, Inc. (Phase II)

Replaced by and project completed by: DYNALECTRIC Company

Schedule Improvement Achieved in Two Major Construction Phases:

Employs two redundant fiber optic highways - Highway 1 and Highway 2.Each highway has CW (clockwise) and CCW (counter clockwise) loops for maximum highway security.

Total system up-date time is 1/2 second.

System incorporates two separate control rooms. Each control room is remote from the other.

Each Control Room contains two multi-operator stations. The entire distributed control system may be observed and/or controlled from any one multi-operator station.

The system contains a separate PC which is data fed by the total control system and is used to develop maintenance management schedules provided at pre-selected issue times.

The system contains a separate MicroVAX facility which is data fed by the total control system. This data is integrated and accumulated within the MicroVAX and then issues separate daily, weekly, and monthly reports of utility consumption and plant production.

The system provides five PCs which serve as local operator panels for monitoring and limited control at DCU (Distributed Control Unit) field locations.

The total system includes eight printers which are dedicated to alarm monitoring, operators monitoring and report production.

Leeds+Northrup MAX 1 DCS with the following components:

(2) Fiber-optic Data Highways

(12) Pairs Optical/Electrical Interface (OEI) Modules

(4) Operator Stations

(10) Controller Files in air-conditioned cabinets

(5) IBM Compatible PC consoles for remote operator control functions

(8) Printers

(1) MicroVAX Unit

1. Bernoulli Box with removable cartridge for use in link with

1. IBM PC & Monitor for Maintenance Management System

2160 Total I/O Supplied: 500 AI 100 AO 1088 DI 432 DO 40 RTD

The Distributed Control Unit (DCU) and Distributed Operators Console (DOC) assignments are as follows:

Each unit provides control and cooling of No. 1 and No. 2 Turbine Drive Engines, and monitors generation. Controls and monitors digester heating and pumping facilities. Manages sludge and gas distribution systems. Monitors gas detection system.

I/O Provided:

120 Analog Inputs 128 Digital Inputs

16 Analog Outputs 64 Digital Outputs

Regulates scum level, heating, mixing, and pumping. Provides clarifier drives control. Monitors screening. Area H2S and CH4.

I/O Provided:

30 Analog Inputs (4-20mA) 80 Digital Inputs

40 RTD Temperature 32 Digital Outputs

12 Analog Outputs

Provides aeration blower control, room ventilation, aeration flow control to aeration tanks. Monitors power. Contains six 600 HP blowers and one 900 HP blower with participation time control and monitoring. 900 HP blower rated at 17,900 ICFM. 600 HP blowers are rated at 9,300 ICFM each. Measures and controls dissolved oxygen in the aeration tanks. Anti-surge protection for the blowers. Regulates blowing room ventilation louvers to maintain blowing room temperature. Regulates sanitary sewer pumping stations.

I/O Provided:

80 Analog Inputs 64 Digital Inputs

16 Analog Outputs 64 Digital Outputs

Provides control and monitoring of D.A.F. thickener complex, Thickeners #1 through #6. Top and bottom skimmers, W.A.S. flow, polymer, and sludge pumps. Monitors power in DCU-4 area, monitors H2S concentration.

I/O Provided:

50 Analog Inputs 80 Digital Inputs

8 Analog Outputs 16 Digital Outputs

Controls gate positions on Nitrification Clarifiers #1 through #10. Controls wet well levels. Provides three separate and individual programs to regulate participation of variable speed pumps and constant speed pumps in order to maintain wet well levels with respect to the number of wells in service at any given period.

I/O Provided:

50 Analog Inputs 240 Digital Inputs

8 Analog Outputs 64 Digital Outputs

Regulates flow through Parshall Flumes #1, #2 & #3. Totalizes flow. Controls and monitors scum concentrators at the bar screen, grit, and scum concentrator building. Controls top skimmers and screw conveyor motors.

I/O Provided:

50 Analog Inputs 64 Digital Inputs

8 Analog Outputs 16 Digital Outputs

Modulates influent flow, provides flow splitting between new and old primary treatment areas. Regulates position of Gates #1 through #6. Controls Scum Concentrators, Top Skimmer Drives #1 through #6, Outlet Screw Conveyors #1 through #6, Bottom Screw Conveyors #1 through #6, Slide Gates #7 through #22; as well as Ventilation Fans, Channel Aeration Blower, Odor Control System, Power Monitoring.

I/O Provided:

30 Analog Inputs 128 Digital Inputs

8 Analog Outputs 80 Digital Outputs

Control function similar to DCU-5.

I/O Provided:

60 Analog Inputs 224 Digital Inputs

16 Analog Outputs 64 Digital Outputs

Controls Effluent Pumps #1 through #5; Plant Water Pumps #1 through #4; Elevated Tank Level; Effluent Discharge Gates #6, #7, & #8; Sanitary Pump Station Pumps #1 and #2; Stormwater Pump Station Pumps #1, #2, #3; Chlorine System; Gas Monitors and Evaporators; and Plant Water Booster Pump. Monitors effluent Ph and Temperature.

I/O Provided:

30 Analog Inputs 80 Digital Inputs

8 Analog Outputs 32 Digital Outputs